1. The Field of the Invention
This invention is in the field of therapy units associated with liquid-filled containers. More specifically, this invention relates to portable spas.
2. The Relevant Technology
In ancient times, hydrotherapy was enjoyed by those who were privileged enough to have access to a heated pool or natural mineral spa. Since then, hydrotherapy has been known for its many therapeutic benefits and for the enjoyment and pleasure derived therefrom.
In more recent times, spas, commonly known as hot tubs, have become popular devices in gymnasium facilities, adjacent indoor and outdoor pools, and as freestanding fixtures in individual homes and yards. Such spas are typically comprised of a water-filled container, a pump for circulating water within the container, a heating system for heating the water, a filter for filtering the water and related plumbing and electronics.
In typical spas, these components are permanently built into the walls of the container. Water within the spa container flows out of the container through ports in the wall of the container into a pump unit, which then discharges the water back into the container. A temperature regulator regulates the temperature of the water within the spa and maintains the temperature at a desired, preset level over a series of days, weeks, and months at a time. The filter is designed to clean the water on an ongoing basis.
However, such spas having permanently built-in plumbing and pumping systems tend to be large, expensive, and difficult to transport. In order to move such a unit, a truck or trailer is typically required along with significant manpower in order to hoist the spa from the original position onto the means of transport and then to again lift the spa from the means of transport to a new location. Upon arriving at the new location, such self-contained units are also difficult to orient in the precisely desired position.
As a result of the cumbersome nature of these spas, attempts have been made to design and manufacture portable spas. Portable spas typically include a portable container and a detachable pump unit positioned outside the container. In order to provide the jetting action of the water disposed within the container, the container has a hole within a wall thereof through which inlet and outlet pipes are placed. These through-the-wall plumbing designs permit the pumping of water between the inside portion of the container and the pump unit. After use, the pumping unit is detached from the container and the container and pumping unit are transported to another desired location.
The difficulty associated with such through-the-wall plumbing designs is that water tends to leak through the holes in the wall of the container. Although attempts can be made to seal the interface between the pipes and the container, such as by attempting to permanently couple pipes through a hole in a liner which is removably coupled to a container, it is difficult to maintain the seal between the pipes and the liner on an ongoing basis. The difficulty with maintaining the seal is compounded when the spa is moved from one location to another with the accompanying jostling of the interface between the pipes and the liner. Although sealing rings have been used to seal these types of through-the-wall units, the sealing interface can nevertheless break-down and degrade.
As another alternative for those desiring to enjoy the benefits of hydrotherapy without investing in a spa having permanently built in plumbing or a portable spa having a through-the-wall pumping unit, it is possible to purchase a U-shaped whirlpool apparatus which fits over the side of a bathtub. Generally, such whirlpool apparatuses are configured to jet water in the bathtub through ports in the apparatus.
The water in the bathtub is typically clean, warm water. Because they are not designed for long-term use as in the case of spas, typical U-shaped bathtub whirlpool apparatuses do not include a filter for filtering the water in the bathtub. As opposed to spas, bathtub water is typically designed for temporary use, after which the water is discharged through the drain. Similarly, the temperature of the water in bathtubs is controlled by adding additional hot water or cold water from the bathtub taps while bathing. As a result, typical U-shaped bathtub whirlpool devices are not designed to heat the water within the bathtub. Instead, these bathtub whirlpool devices rely on a fresh amount of water which has been warmed to a desired temperature through the use of manual controls on the bathtub.
Also because of their reliance on hot water from the bathtub plumbing, typical U-shaped bathtub-type jetting devices fail to monitor the temperature of the liquid within the bathtub. In the event the device were to be used in an outdoor setting, for example, and the user were to fail to place hot water in the bathtub, the water within the tub could freeze and thereby damage the plumbing within the tub.
Typical over-the-side units employ a pumping mechanism comprising an impeller submerged within the water within a container. In these devices, water flows from the container into the pumping mechanism and remains within the submerged pumping mechanism until it is dispelled back into the container. Manufacturers of typical units take overt measures to prevent water within the pumping mechanism from seeping into portions of the unit higher than the pumping mechanism, such as by sealing the interface between the pumping mechanism and the remainder of the unit. This prevents the water from being pumped to locations other than the submerged pumping mechanism before being discharged back into the container.
In addition, typical U-shaped bathtub pumping mechanisms tend to focus their jetting action exclusively on one portion of the user's body. Certain bathtub-type devices attempt to ameliorate the problem with such exclusive, focused jetting action by employing a variety of different ports located in scattered positions throughout the bathtub. U.S. Pat. No. 5,404,598 to Hadsell, for example, discloses a bathtub hydrotherapy add-on apparatus which includes a pump placed on the outside of the bath tub and a plurality of flexible hoses placed in a number of different sites of the bathtub.
Although the apparatus can be used to jet water from different locations within the bathtub, the hoses must be individually positioned by a user for each new use. Furthermore, each hose must be removed individually after each use. In addition, each of the hoses must be gathered together in order to move and store the apparatus without dragging the hoses on the floor or leaving the hoses in a disorganized pile.
There is therefore a need within the art for a portable spa system which heats and circulates liquid within the system without relying on the user to constantly replace cool, dirty water with fresh, warm water. There is also a need for such a portable spa system which is not susceptible to leaking of the water through the wall of a container and does not require the user to place disorganized hoses in different locations in the container.